EFFECT OF IRRADIATION AND PACKAGING MATERIALS TYPES ON SHELF-LIFE AND QUALITY ATTRIBUTES OF MINCED MEAT DURING COLD STORAGE

Minced meat is considered one of the most meat products that exposed to contamination which led to many changes in its quality and reduced its shelf-life.Therefore, this investigation was carried out to extend the shelf-life of minced meat for consumption and maintaining its quality during cold storage by using irradiation with various doses (3, 6 and 9 kGy) and different packing materials. The results indicated that irradiation,especially at 3 and 6 kGy, had no effect on chemical composition and some physical properties of minced meat. On the other hand, pH values of all irradiated samples were slightly decreased with decreasing irradiation doses.Irradiation at the highest dose used, i.e. 9 kGy, slightly increased total volatile nitrogen (TVN) of minced meat. Thiobarbituric acid (TBA) value of irradiated samples was tended to increase with increasing irradiation dose from 3 to 9 kGy either directly after irradiation or during storage.Regardless of irradiation effect on TVN and TBA values at zero time, there were no marked differences in TVN and TBA values of irradiated minced meat according to differentiate packaging materials (PE, PA/PE and PET/Al/PE). During cold storage, the TVN and TBA values of all minced meat samples either non-irradiated or irradiated were progressively increased as the time of cold storage increased. The higher increasing rate in TVN and TBA of irradiated samples was recorded for samples packaged in PE (one layer) followed by PA/PE (two layers) and finally PET/Al/PE (three layers) at the same irradiation dose. Irradiation of minced meat with 3 kGy reduced the counts of total bacteria, coliform bacteria, Staphylococcus aureus and yeasts and molds counts as well as eliminating Salmonella spp. Irradiation doses of 6 and 9 kGy completely eliminated coliform bacteria, Staphylococcus aureus and yeasts and molds. Also, type of packaging materials which used had no effect on counts of all studied microorganisms. Irradiation of minced meat with different doses (3, 6 and 9 kGy) had no significant effects on overall acceptability. From these results, it could be noticed that, the utilization of 6 and 9 kGy of irradiation doses beside the usage of PET/Al/PE (three layers) were the best which led to extend the shelf-life of minced meat to 4 and 5 weeks, respectively